Do fish urinate?

This is a discussion on Do fish urinate? within the Freshwater and Tropical Fish forums, part of the Freshwater Fish and Aquariums category; -->
Originally Posted by MoneyMitch
you confuse me lol
The water and pee are different densities which creates the &quot;oil in water&quot; effect as the ...

Just curious - where did you see that guppies urinate a third of their body mass?

I don't know if there is a significant difference between species when it comes to urine released, since it is, as Quantum mentioned earlier, related to osmoregulation. I do know that tetra can expel this much daily.

Urination is the fish's way of getting rid of all the water it takes in via osmosis through the cells, and this is partially determined by the TDS (total dissolved solids, which incudes the GH) in the tank water, one reason why this is so critical. If anyone wants to read a bit further on this, in fairly simple terms, check out my article on the effects of TDS as it it significant to this,http://www.tropicalfishkeeping.com/f...uarium-122027/
and my article on Stress mentions it too:http://www.tropicalfishkeeping.com/f...um-fish-98852/

Just curious - where did you see that guppies urinate a third of their body mass?

It wasn't specifically guppies and I couldn't find it again... one of those articles that mentioned how much while describing the process and why it was so much, in reference to freshwater fish generally.

I never used to keep links to interesting articles but it would be handy when commenting to provide reference... I've started doing so more recently though. Nice to be able to go back and re-read some of them. Sometimes finding it the second time is easier said than done.